some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.
Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.
We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths. Do, however, move those prototypes to priv.h.
Reviewed by: csjp
Obtained from: TrustedBSD Project
In dounmount(), before or while vn_lock(coveredvp) is called, coveredvp
vnode may be VI_DOOMED due to one of the following:
- other thread finished unmount and vput()ed it, and vnode was chosen
for recycling, while vn_lock() slept;
- forced unmount of the coveredvp->v_mount fs.
In the first case, next check for changed v_mountedhere or mnt_gen counter
would be successfull. In the second case, the unmount shall be allowed.
Submitted by: sobomax
MFC after: 2 weeks
- We need to allow for PRIV_VFS_MOUNT_OWNER inside a jail.
- Move security checks to vfs_suser() and deny unmounting and updating
for jailed root from different jails, etc.
OK'ed by: rwatson
unmount jail-friendly file systems from within a jail.
Precisely it grants PRIV_VFS_MOUNT, PRIV_VFS_UNMOUNT and
PRIV_VFS_MOUNT_NONUSER privileges for a jailed super-user.
It is turned off by default.
A jail-friendly file system is a file system which driver registers
itself with VFCF_JAIL flag via VFS_SET(9) API.
The lsvfs(1) command can be used to see which file systems are
jail-friendly ones.
There currently no jail-friendly file systems, ZFS will be the first one.
In the future we may consider marking file systems like nullfs as
jail-friendly.
Reviewed by: rwatson
and flags with an sxlock. This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention. All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently. Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.
- Generally eliminate the distinction between "fast" and regular
acquisisition of the filedesc lock; the plan is that they will now all
be fast. Change all locking instances to either shared or exclusive
locks.
- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
was called without the mutex held; sx_sleep() is now always called with
the sxlock held exclusively.
- Universally hold the struct file lock over changes to struct file,
rather than the filedesc lock or no lock. Always update the f_ops
field last. A further memory barrier is required here in the future
(discussed with jhb).
- Improve locking and reference management in linux_at(), which fails to
properly acquire vnode references before using vnode pointers. Annotate
improper use of vn_fullpath(), which will be replaced at a future date.
In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).
Tested by: kris
Discussed with: jhb, kris, attilio, jeff
vfs_flags field is used for VFCF_* flags which are given at file system
driver creation time (via VFS_SET(9)) macro.
What this code did was bascially this:
If file system registers itself with VFCF_UNICODE flag (stores file names
as Unicode), it will gain MNT_SOFTDEP flag (UFS soft-updates).
If file system registers itself with VFCF_LOOPBACK flag (aliases some other
mounted FS), it will gain MNT_SUIDDIR flag (special handling of SUID on
dirs).
The latter will be quite dangerous, but those flags are reset later in
vfs_domount().
MFC after: 1 month
prison_priv_check() to decide what to do.
This change is suppose not to change current (security) behaviour
in any way.
This change is simlar to the change of PRIV_VFS_MOUNT in previous revision.
- Remove also "MP SAFE" after prior "MPSAFE" pass. (suggested by bde)
- Remove extra blank lines in some cases.
- Add extra blank lines in some cases.
- Remove no-op comments consisting solely of the function name, the word
"syscall", or the system call name.
- Add punctuation.
- Re-wrap some comments.
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
unmount when mp structure is reused while waiting for coveredvp lock.
Introduce struct mount generation count, increment it on each reuse and
compare the generations before and after obtaining the coveredvp lock.
Reviewed by: tegge, pjd
Approved by: pjd (mentor)
MFC after: 2 weeks
sync() and sync_fsync() without losing MNT_ASYNC. Add MNTK_ASYNC flag
which is set only when MNT_ASYNC is set and mnt_noasync is zero, and
check that flag instead of MNT_ASYNC before initiating async io.
be recycled during the sleep, wrap the vn_lock with vhold/vdrop.
Check that coveredvp still points to the same mp after sleep (needed
because sleep dropped Giant).
Move check for user rights for unmount after coveredvp lock is obtained.
Tested by: Peter Holm
Reviewed by: tegge
Approved by: kan (mentor)
MFC after: 2 weeks
the 'vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len)'
call fails, 'errmsg' is left uninitialized, making the later tests
against NULL meaningless, and the uses bogus. Thus initialize
'errmsg' to NULL beforehand. [1]
While at it, remove the superfluous assignment of 0 to 'errmsg_len'
if the above mentioned call fails as it's already initialized to 0.
Submitted by: Michael Plass [1]
copyout(9) instead of copystr(9) for copying the errmsg from
kernel- to user-space. This fixes a panic on sparc64 when
using the nmount(2)-converted mountd(8).
While at it, use bcopy(3) instead of strncpy(3) in the kernel-
to kernel-space case for consistency with vfs_buildopts() and
between kernel- to user-space and kernel- to kernel-space case.
from going away. mount(2) is now MPSAFE.
- Expand the scope of Giant some in unmount(2) to protect the mp structure
(or rather, to handle concurrent unmount races) from going away.
umount(2) is now MPSAFE, as well as linux_umount() and linux_oldumount().
- nmount(2) and linux_mount() were already MPSAFE.
forget to unbusy file system before its destruction.
This fixes the following warning on mount failure:
Mount point <X> had 1 dangling refs
Tested by: wkoszek
mount(2) system call:
* Add cmount hook to fdescfs and pseudofs (and, by extension, procfs and
linprocfs). This (mostly) restores the ability to mount these
filesystems using the old mount(2) system call (see below for the
rest of the fix).
* Remove not-NULL check for the data argument from the mount(2) entry
point. Per the mount(2) man page, it is up to the individual
filesystem being mounted to verify data. Or, in the case of procfs,
etc. the filesystem is free to ignore the data parameter if it does
not use it. Enforcing data to be not-NULL in the mount(2) system call
entry point prevented passing NULL to filesystems which ignored the
data pointer value. Apparently, passing NULL was common practice
in such cases, as even our own mount_std(8) used to do it in the
pre-nmount(2) world.
All userland programs in the tree were converted to nmount(2) long ago,
but I've found at least one external program which broke due to this
(presumably unintentional) mount(2) API change. One could argue that
external programs should also be converted to nmount(2), but then there
isn't much point in keeping the mount(2) interface for backward
compatibility if it isn't backward compatible.
mount memory from being reclaimed. This resolves a number of race
conditions described in vfs_default.c and introduced with the
VFS_LOCK_GIANT macros.
- Let the mtx and lock remain valid after the mount structure has been
freed by using init and fini calls. Technically fini will never be
called but is included for completeness.
- Consistently use lockmgr directly rather than lockmgr to lock and
vfs_unbusy to unlock.
Discussed with: tegge
Tested by: kris
Sponsored by: Isilon Systems, Inc.
specified, the rightmost option takes effect." Fix code to obey
this. This makes e.g. "mount -r /usr" or "mount -ar" actually
mount file systems read-only.
replacement for vn_write_suspend_wait() to better account for secondary write
processing.
Close race where secondary writes could be started after ffs_sync() returned
but before the file system was marked as suspended.
Detect if secondary writes or softdep processing occurred during vnode sync
loop in ffs_sync() and retry the loop if needed.
modules prior to looking up the directory which we will cover to avoid
this problem in mount.
- We must hold the coveredvp locked before we can busy the mountpoint to
prevent a lock order reversal with the vfs_busy() in lookup which holds
the directory lock prior to doing a vfs_busy(). The directory lock is
required to safely clear the v_mountedhere field on the directory.
MFC After: 1 week
vfs_mount_destroy waiting for this ref to hit 0. We don't print an
error if we are rebooting as the root mount always retains some refernces
by init proc.
- Acquire a mnt ref for every vnode allocated to a mount point. Drop this
ref only once vdestroy() has been called and the mount has been freed.
- No longer NULL the v_mount pointer in delmntque() so that we may release
the ref after vgone() has been called. This allows us to guarantee
that the mount point structure will be valid until the last vnode has
lost its last ref.
- Fix a few places that rely on checking v_mount to detect recycling.
Sponsored by: Isilon Systems, Inc.
MFC After: 1 week
Since we are using vfs_busy() on a freshly allocated mount structure, use
(void) to show that we do not care about the return value.
Found with: Coverity Prevent (tm)
MFC after: 2 weeks
directly. We need to copyin() the strings in the iovec before
we can strcmp() them. Also, when we want to send the errmsg back
to userspace, we need to copyout()/copystr() the string.
Add a small helper function vfs_getopt_pos() which takes in the
name of an option, and returns the array index of the name in the iovec,
or -1 if not found. This allows us to locate an option in
the iovec without actually manipulating the iovec members. directly via
strcmp().
Noticed by: kris on sparc64
When all file systems have a time stamp of zero, which is the case
for example when the root file system is on a read-only medium, we
ended up not calling inittodr() at all. A potential uncleanliness
existed as well. If multiple file systems had a non-zero time stamp,
we would call inittodr() multiple times. While this should not be
harmful, it's definitely not ideal.
Fix both issues by iterating over the mounted file systems to find
the largest time stamp and call inittodr() exactly once with that
time stamp. This could of course be a zero time stamp if none of the
mounted file systems have a non-zero time stamp. In that case the
annoying errors mentioned in the commit log for revision 1.186 still
haven't been avoided. The bottom line is that inittodr() should not
complain when it gets a time base of zero. At the time of this
commit only alpha seems to have that problem.
Reported by: Dario Freni (saturnero at freesbie dot org)
MFC after: 1 week
is called. It looks like there are lots of different mount flags checked
in vfs_domount(), so we need to do the parsing for these particular
mount flags earlier on. The new flags parsed are:
async, force, multilabel, noasync, noatime, noclusterr, noclusterw,
noexec, nosuid, nosymfollow, snapshot, suiddir, sync, union.
Existing code which uses mount() to mount UFS filesystems is not
affected, but new code which uses nmount() to mount UFS filesystems
should behave better.
in, and if so, set MNT_UPDATE filesystem flag.
vfs_nmount() calls vfs_domount(), and there is special logic
inside vfs_domount() if MNT_UPDATE is set. This is very important
when we want to do an update mount of the root filesystem, using nmount().
to user-space if a parameter named "errmsg" is passed into the iovec.
Used in conjunction with vfs_mount_error(), more useful error messages
than errno can be passed back to userspace when mounting a filesystem
fails.
Discussed with: phk, pjd
While we wait for holds to be released, print a list of who holds us
back once per second.
Use the new KPI from GEOM instead of vfs_mount.c calling g_waitidle().
Use the new KPI also from ata.
With ATAmkIII's newbusification, ata could narrowly miss the window
and ad0 would not exist when we tried to mount root.
actual root file system is mounted, the first entry on the mountlist
is not the root file system and the timestamp for that entry is
typically 0. Passing that to inittodr() caused annoying errors on
alpha and ia64.
So, call inittodr() for all file systems on mountlist, but only when
the timestamp (mnt_time) is non-zero.
it to get better hashing in vfs_hash.
In case of an insert collision in vfs_hash_insert(), put the loosing vnode
on a special list so that vfs_hash_remove() can just assume that it is on
a list.
Drop the VI_HASHED flag.
- Add buffer size limitations (overflow will not be possible anymore).
- Add 'visible' option, which will allow for passphrase reading in the
future.
- Remove special treatment of '@' and '#', those two are only confusing.
Discussed with: rwatson
MFC after: 2 weeks
I'm not sure why a credential was added to these in the first place, it is
not used anywhere and it doesn't make much sense:
The credentials for syncing a file (ability to write to the
file) should be checked at the system call level.
Credentials for syncing one or more filesystems ("none")
should be checked at the system call level as well.
If the filesystem implementation needs a particular credential
to carry out the syncing it would logically have to the
cached mount credential, or a credential cached along with
any delayed write data.
Discussed with: rwatson
split the conversion of the remaining three filesystems out from the root
mounting changes, so in one go:
cd9660:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
nfs(client):
Convert to nmount (the simple way, mount_nfs(8) is still necessary).
Add omount compat shims.
Drop COMPAT_PRELITE2 mount arg compatibility.
ffs:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
Remove vfs_omount() method, all filesystems are now converted.
Remove MNTK_WANTRDWR, handling RO/RW conversions is a filesystem
task, and they all do it now.
Change rootmounting to use DEVFS trampoline:
vfs_mount.c:
Mount devfs on /. Devfs needs no 'from' so this is clean.
symlink /dev to /. This makes it possible to lookup /dev/foo.
Mount "real" root filesystem on /.
Surgically move the devfs mountpoint from under the real root
filesystem onto /dev in the real root filesystem.
Remove now unnecessary getdiskbyname().
kern_init.c:
Don't do devfs mounting and rootvnode assignment here, it was
already handled by vfs_mount.c.
Remove now unused bdevvp(), addaliasu() and addalias(). Put the
few necessary lines in devfs where they belong. This eliminates the
second-last source of bogo vnodes, leaving only the lemming-syncer.
Remove rootdev variable, it doesn't give meaning in a global context and
was not trustworth anyway. Correct information is provided by
statfs(/).
vfs_flagopt() for binary/boolean options.
vfs_getopts() for string options
vfs_filteropt() to check for unknown options.
vfs_scanopt() for scanf() like processing of options.
Also add function for setting the stat.f_mntfromname field.
